Organic Vesicles Captured by In-Situ Reduction of Gold

 The partially hydrolyzed polyacrylamide (HPAM) and hydroxyethyl hydroxyethyl cellulose (HEC) can self-assembled into vesicles in aqueous solution. The experimental results showed that HPAM-HEC would self-assemble into the half-moon miltivesicular vesicles of 500 nm ×300 nm ×50 nm at pH 1.3 and collapse to disintegrate into 10 nm pseudo spherical polymer micelles at pH 0.9. When the vesicles were investigated by transmission electron microscopy (TEM), it seems difficult to get clear TEM images as a result of low contrast of these macromolecules. In this paper HAuCl₄ was added into the system and the gold was in-situ reduced at self-assembled particle surface thus increased the electron density of vesicles, so that we can get clear TEM images which verify the occurrence of the nano-opening or hole on the surface of large miltivesicular vesicles and the disintegrating process composed of HPAM and HEC.